The corona discharge, its properties and specific uses

Abstract

The main properties of corona discharges are reviewed, with emphasis on the features which make them unique for use as non-equilibrium chemical reactors : Their stability and ease of operation over a wide range of gases and pressures, including atmospheric ; their sharply confined ionization regions where hot electrons interact with cold gas, inducing reactions without back reactions ; and their extended low field drift regions which act as gaseous electrolytes, inducing electrochemical reactions on surfaces. Present and future applications are discussed : Synthesis of ozone and ammonia, promotion of flames and combustion, surface treatment, and electrical insulation improvement.

Corona Discharge Velocimeter

“…For a given range of voltages V HV above a threshold V s , the electric current I consists in regular pulses (known as "Trichel pulses"), with a repetition rate around a few hundred kilohertz (far higher than audio frequencies: 20 Hz -20 kHz). As the voltage is increased, the pulses turn into a steady-state current regime (glow discharge) until a spark occurs [2,8,10,14,13,26]. In the "Trichel pulses" regime, the frequency of the pulses depends on various factors such as the geometrical and electrical configurations of the electrodes but also on the surface properties.…”

Physics of self-sustained oscillations in the positive glow corona

“…The minor discrepancies in the electrode current waveforms between the result of this work and the experimental measurements by others can be attributed to the differences in the setup of the apparatus. [2][3][4][5][6] Illustrated in Fig. 16(a) is the equivalent circuit diagram representation for a typical apparatus in the glow corona experiments.…”

“…Besides the geometrical differences in the anode, the model treated here has only a single charged-particle in the space between the anode and the cathode whereas, in the glow corona experiments, 2,3,5 the space between the electrodes is filled with an ionized gas, i.e., many ionized atoms. Despite these differences, the theory qualitatively reproduces the self-sustained current oscillations in the electrode, consistent with the results from the various glow corona experiments.…”

“…To this date, the basic underlying mechanism behind such self-sustained current oscillations remains unclear. [2][3][4][5][6] Morrow did a theoretical work in an attempt to explain the underlying physics behind the self-sustained current oscillations in the positive glow corona. 4 Qualitatively, his predictions are consistent with the various experimental observations by others.…”

“…[2][3][4][5][6] The selfsustained pulsing in the positive glow corona (also referred to as direct current (DC) glow discharge) can be qualitatively explained from the aforementioned, oscillating, chargedparticle dynamics. In this paper, I shall show that the selfsustained pulsing in the positive glow corona involves the kind of charged-particle oscillation mechanism discussed in Figs.…”